1. Technical Field
The present application relates generally to an antenna for receiving radio signals in a radio paging receiver and, more particularly, to a multiple loop antenna for use in a radio paging receiver.
2. Description of the Related Art
In accordance with the continued goal of designing smaller and lighter products, manufactures of conventional radio paging receivers have widely utilized loop antennas in their radio paging receivers due to their small size and light weight. Referring to FIG. 1, an exploded view of a radio paging receiver having a conventional loop antenna is shown. In general, the radio paging receiver includes a case 1, a radio frequency (RF) board 2, and a loop antenna 3.
Referring to FIGS. 2A and 2B, the relationship between an electric field E and a magnetic field M and the position of the conventional loop antenna 3 with respect to the direction of travel of a radio signal is shown. The loop antenna 3 is a directional antenna which exhibits a different receiving sensitivity based on its position with respect to the direction of travel of the electromagnetic radio wave. In particular, the single loop antenna 3 used in the radio paging receiver exhibits maximum receiving sensitivity when reacting to the magnetic field component of the radio signal, whereas the single loop antenna 3 exhibits significantly lowered sensitivity when reacting to the electric field component of the radio signal. For instance, the loop antenna 3 exhibits maximum receiving sensitivity when the loop antenna is positioned as indicated in FIG. 2A with respect to the given direction of travel of the radio wave since the loop antenna significantly reacts to the magnetic field component M of the radio wave. On the other hand, the loop antenna 3 exhibits minimum receiving sensitivity when it is positioned as shown in FIG. 2B since it reacts to the electric field component E (as opposed to the magnetic field component M) of the radio wave.